Fluid-compressor



(No4 Model.)

F. M. BITES. FLUID COMPRESSOR.

Atty.

Patented Oct. 6,-1896.

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FRANCIS M. BITES, OF PITTSBURG, PENNSYLVANIA.

FLUID-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 568,796, dated October6, 1896.

Application led December 9, 1895. Serial No. 571,501. (No model.)

Tov all whom it may concern;

Be it known that I, FRANCIS M. Rrrns, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered a certain new and usefulImprovement in Fluid-Compressors, of which improvement the following isa speciiication.

The object of my invention is to provide means for varying the period ofoperation of the positively-operated valves of a huid-coinpressor, theoperation of which valves is eftected and maintained by the mechanism ofthe compressor or motor, and to enable the compressor to be run at ahigh rate of speed Without imposing strains on the governing mechanism.

To this end my invention, generally stated, consists in the combination,with a motorcylinder and a compressor-cylinder, of an adjustablevalve-gear and a valve for the compressor-cylinder connected theretoWhose operation is effected and maintained by the motor, but whoserelative periods of operation are varied by a governor under theinfluences of pressures within and without the compressor-cylinder.

The improvement claimed is hereinafter fully set forth. o

My invention is not limited in application to the specific form ofvalve-gear herein set forth, but may be employed in connection with anyof the usual forms of adjustable valve mechanism or with any form ofvalve mechanism in which the functions of the valves are adapted to beautomatically varied.

In the accompanying drawings, Figure lis a side elevation of acompressor, showing an application of my improvement in connection withan Allan valve-gear; Fig. 2, a vertical longitudinal section, on anenlarged scale, through the cylinder and valve of the pressure-governorand through the cylinder of the device which directly effects thevariations in the adjustment of the valve-gear of thecompressor-cylinder5 Fig. 3, a vertical longitudinal section on the line0c @c of Fig. 4, through a valve device for controlling the admission offluid from the compressor-cylinder to the cylinder of thepressure-governing device, the means for actuating the admission-valvebeing shown in elevation; and Fig. 4c, a horizontal section of theadmissionvalve device and a plan view of the actuating mechanism for theadmission-valve.

InK the practice of my invention as exemplilied in the drawings Iprovide a compressor in which the valve-gear of the steam-cylinder 1 andthe valve-gear of the air-compressing cylinder 2 are operated by asingle eccentric 4 on the main shaft 5, both valvegears being connectedwith an Allan link 3, which is actuated by the eccentric.

The valve-stem 6 of the steam-distribution valve is connected to anoscillating arm 50 and, by means of a rod 7, with a block S, which isadapted to slide in the link 3. The block Sis adjusted in position bythe centrifugal governor 9, which is connected to the rod 7 by means ofthe lever 1Q and link 1l or which may be connected more directly to theblock The air-com pressing cylinder 2 may be provided with oscillatinginlet and outlet valves of any of the usual forms.

The arms l2 and l2n on the stems of the inlet-valves are connected bymeansof rods 13 and 13 with an oscillating wrist-plate 14, which isconnected with the link 3 by means of the rod l5.

The arms 16 and lOL on the stems of the ou tlet-valves are connectedtogether by means of a rod 17, and also connected, by means of a rod 17,with an oscillatingarm 18, which is mounted ou the frame of the engine.The oscillating arm 18 is connected by means of a rod 19 with a block20, fitted to slide in the slot 3 of the Allan link 3.

It will be seen that with this construction the inlet and outlet valvesof the air-compressing cylinder and the distribution-valve of thesteam-cylinder are all actuated by the single eccentric 4t onv the mainshaft 5. The valvegear for operating the outlet-valves of theair-compressing cylinder and the valve-gear for operating thedistribution-valve of the steam-cylinder are adapted to be adjusted byshifting the sliding blocks 2O and 8, respectively, in the slot 3n ofthe link 3. The adjustment of the valve-gear of the steam-cylinder iseffected by means of the centrifugal governor 9, which operatesautomatically to shift the block S, and the adjustment of the IOOvalve-gear which operates the outlet-valves ot the compressing-cylinderis effected by means of my improved governing` 1n eehanism which willnow be described.

In the embodiment of my invention shown in the drawings a lever 2l,which is shown pivoted to the base or frame of the centrifugal govenor,is connected at one end to the rod l!) by means of a rod 22, and at itsother end, by means of a link 23, to the rod 24 of a pist-011 25, (shownin Fig. 2,) which is fitted to work in a cylinder 2G.

1f preferred, the rod 22 may connect directly to the block .20, theobject of the connection being that the block 20 may be adjusted inposition relative to the lilik 3 by the movement of the lever 21. Themovement of the lever 2l for this purpose is eiiected by the movement ofthe piston 25, which is actuated by lluid under pressure in the cylinder2G, the admission and release of the fluid to and from opposite sides ofthe piston 25 being controlled by the valve 27.

The fiuid by which the piston 25 is actuated may be obtained from anyconvenient source of iiuid under pressure, but in order to insure aconstant supply of fluid under pressure which will always be availableindependently of the operation of the compressor, and which will be ofsubstantially uniform pressure, I prefer to employ in the constructionshown the pressure from a water-main or some other permanent reservoirof pressure, which in this instance is connected with the valvechamber2S by means of the passage 4U, which opens into the valve-chamber 28between the ends ol the valve 27.

The valve 27 is connected by means of a stem 2.) with a floating lever30, which is con nected at one en d to the stem 24 of the piston 25 andat its other end to the stem 3l oi a piston in the small cylinder 33.

One end ot' the cylinder 33 is connected by means of a pi pc 34 with theoutlet-passage ofthe lluid-comjnessing cylinder 2 or with the reservoirinto which the iluid is compressed, and one side of the piston 32 isthus at all times exposed to the pressure in the outlet or in thereservoir of the Huid-compressor. l The other end of the cylinder is connccl'ed by means ol a pipe 3o' with branch pipes 37, leading to oppositeends ofthe {inidcompressing cylinder 2, through which fluid may beadmitted from either end of the coinpressi11g-cylinder to one side ofthe piston 32 in the cylinder 33.

As it is not desirable that either end of the compressing-cylindershould be at all times in communication with the cylinder I elnployvalves 3!) in the easing-s 38 and 3S:L (shown in section in Figs. 3 and4) for closing communication from each end of the cylinder 2, throughthe branch pipes 37, to the pipe 36 and cylinder 33, and provide meansfor opening the valves 3S) when it is desired to put the cylinder 33 incommunication with eitherend of the compressing-cylinder 2.

The valves 39 are normally held to their seats by means of springs 40and are provided with stems 41, which pass through the stuffing-boxes 42and extend into position to be actuated by the tappets 43, which arepivoted on the arms lo and 1G:L of the outletvalves.

Then the arm 1G is turning in the direction indicated by the arrowinFig. 3, the tappet 43 is held against the stop 44 by the spring 45, oneend of which bears against the tappet and the other end of which isseemed to the stop 44, and when the tappet comes in contact with thestem 4l the valve 3f) is unseated, so as to admit iluid from the end ofthe compressing-cylinder 2 to the pipe 3G and cylinder 33. \Vhcn the arm1U is moving in the opposite direction and the tappet comes in contactwith the stem 4l, the spring 45 yields and permits the tappet to pass bythe stem without opening the valve. The valves 39 are held closed by thesprings 40, except when unseal'ed by the contact ot' the tappets 43 withthe stems 41, and the positions of the tappets 43 on the arms lo' and 16are such that each tappet will come in contact with one of the stems 4land unseat one of the valves 3S) just before the outlet-valve atthat endof the compressing-eylinder is opened. Communication is thus openedthrough the pipes 37 and 3G between one end of the compressing-cylinderand the upper end oi the cylinder at each stroke of the piston in thecompressor-cylinder, and the small piston 32 in the cylinder 33 isexposed on one side to the pressure of the compressed i'luid in thecompressing-cylinder just before the outletvalve at the end of thecomprcssing-cylinder opens, and the closing of the valve 39, which isthen elee-ted by the spring 40, prevents a reduction of pressure in thecylinder above the piston 32, such as would occur if communicationbetween the compressing-cylinder a-nd the small cylinder remained openaiter the opening of the outlet-valves of the eompressingcylinder. Theclosing of the valve 39 also prevents the small piston 32 from being)1subjected to the variations of pressure which occur at other times inthe compressing-cylinder.

It will be understood that each of the casings 38 and 3S*L contains avalve device similar to that shown in Figs. 3 and 4; that both of thesevalves'remain closed except during the time that they are momentarilyopened by the tappets 43, and that the opening and closing movements ofeach of the admissionvalves 3f) always occur just bci-'ore the openingof the outlet-valve on the saine end of the compressor-cylinder. Theresult of this operation is that the only pressure admitted to the upperend of the small cylinder is the maximum pressure which exists in thecompressor-cylinder just before the opening of the outlet-valves.

So long as the pressure in the reservoir or outlet-passage of thecompressing-cylinder IOO IIO

and the maximum pressure which exists in the compressing-cylinder justbefore the opening of the outlet-valves substantially balance oneanother the opposing pressures on the opposite sides of the small piston32 will balance one another and there will be no movement of the piston32, the valve 27 will be held in its middle position, so as to close theports 47 and 4S, the piston 25 will not be moved to change theadjustment of the block 20 in the link 3, and there will be no variationin the time of opening of the outlet-valves.

If the adjustment of the block 2O in the link 3 is such that theoutlet-valves are opened before the pressure of the fluid which is beingcompressed in the compressor-cylinder equals the pressure in theoutlet-passage or reservoir of the compressor, or if the adjustment issuch that the outlet-valves do not open until the pressure in thecompressing-cylinder is considerable in excess of the pressure in theoutlet-passage or reservoir, there will be a corresponding difference ofpressures acting on the opposite sides of the piston 32, the piston 32will be moved, so as to shift the valve 27 from its middle position, oneof the ports 47 or 48 in the cylinder 26 will be opened to admit fluidunder pressure from the passage 46 to one side of the piston 25, and theother port at the opposite end of the cylinder 2 6 will be opened topermit the escape of fluid from the other side of the piston 25, throughthe valve 27, to the exhaustpassage 49, and the piston 25 will be movedby the fluid under pressure from the passage 46 tov operate the lever 21and shift the position of the block 20 in the link 3 in direction toeffect the desired variation in the time of opening the outlet-valves.

If the press-ure of the fluid admitted from the compressor-cylinder tothe small cylinder is less than the reservoir-pressure acting on theother side of the small piston, the small piston 32 and the valve 27will be moved upward, the water main or other independent source offluid under pressure which is connected to the opening 46 will be put incommunication with the upper end of the cylinder 26, the lower end ofthe cylinder 26 will be put in communication with the exhaust or drainpipe 49, and the piston 25 will be moved downward. The downward movementof the piston 25, acting through the lever 2l, will cause an upwardmovement of the block 20 toward the center of the link 3, and thevalve-gear for operating the outlet-valves will thereby be adjusted toeffect a later opening` of the outlet-valves. In case the pressure ofthe fluid admitted from the compressor-cylinder to the small cylinder 33is sufficiently greater than the reservoir-pressure to cause a downwardmovement of the piston 32, the valve 27 will also be moved downward, thelower end of the cylinder 26 to the exhaust or drain pipe 49, the piston25 will be moved upward, the lever 2l will be actuated to move the block2O downward toward the end of the link 3, and the outletvalve gear willthereby be adj usted to effect an earlier opening of the outlet-valves.

In whatever direction the valve 27 is moved by the small piston 32, thepiston 25 will be moved in the opposite direction to effect the properadjustment of the outlet-valve gear, and the same movement of the piston25 which effects adjustment of the valve-gear will, by means of thelever 30, move the valve 27 back to its central position, in whichposition the valve 27 covers both of the ports 47 and 48 at oppositeends of the cylinder 26 and confines the fluid in both ends of thecylinder 26. The confined iiuid on opposite sides of the piston 25 willthen tend to check or prevent any vertical vibratory movement of the endof the rod 23 or of the rod 19.

After the adjustment of the block 2O to effect the opening of theoutlet-valves at the proper time, that is, to effect the opening of theoutlet-valves at the time when the pressure in the com pressing-cylinderbears the proper relation to the pressure in the outlet passages andreservoir, these two pressures will be approximately equal, and thepiston 32 in the small cylinder 33 will be substantially balanced by thepressures on its opposite sides and will be unaffected by any vibrationsof the valve mechanism whose adjustment it controls. In the drawings,the area of 'that side of the piston 32 on which the reservoir-pressureacts is greater than the area of the opposite side,.0n which thepressure in the compressing-cylinder acts, the difference being equal tothe cross-sectional area of the piston-rod 3l, and the piston 32 is tothat extent a differential piston. This difference in area may beincreased or diminished, as found desirable, by enlarging or diminishingthe cross-sectional area of the piston or by other means, or anequivalent result may be obtained by the employment of a spring orweight on one side of the piston to offer additional resistance topressure on the opposite side. I make no claim to any specificconstruction for this purpose, but merely indicate that the constructionand proportions may be varied without departure from my invention.

The diameter of the piston 32 may be very small, as it is only necessarythat the area of the piston should be sufficient to permit thedifference of pressures on its opposite sides to move the small balancedvalve 27. rlhe pipe 36, which connects one end of the small cylinder 33with the ends of the air-compressing cylinder 2, may be of such smalldiameter that it will contain but a small volume of fluid, and thevolume of the cylinder 33 on one side of the piston 32, together withthe volume of the pipe 36, will, when the valve 39 is open, add but verylittle to the clearance at the ends of the air-compressing cyl- IOC IIO

inder. This is of importance in all Huid-compressors, but it is ofspecial importance in lluid compressors employed in connection withrefrigerating appi'n'a-tus.

I claim as my invention and desire to secure by Letters Paten tl. In anelastic Iluid-compressor, the combination, of a compressing-cylinder,valve mechanism controlling the valves of said cylinder, and soconnected with the motor as to be positively and continuously operatedby the motor during the whole of the cycle of operation of thecompressor, a pressureaetuated device connected to and actin to vary theop eration of said valve mechanism, and con nections from thecompressor-cylinder and from the outlet passage or reservoir of thecompressor to the pressure-actuated governing device, whereby theadjustment of the valve mechanism is effected by the opposing pressuresof the fluid in the cylinder and in the outlet passage or reservoir ofthe compressor, substantially as set forth.

2. In an elastic fluid-compressor, the com.- bination, ofacompressorcylinder, valve mechanism controlling the valves of saidcylinder and so connected with the motor as to be positively andcontinuously operated by the motor during the whole of the cycle ofoperation of the compressor, a fluid-pressure actuated device foreffecting the adjustment of the valve mechanism and means whereby theoperation of the fluid-pressure-actuated device is controlled bytheopposing pressures of the iiuid in the compressor-cylinder and in theoutlet passage or reservoir of the compressor, substantially as setforth.

In an elastic iluid-compressor, the combination, of a motor, acompressor-eylinder, valve mechanism receiving motion from the motorthrough an adjustable linli connection f or directly operating thevalves of the co1n pressoucylimler from the motor, and aIiuidpressurc-governing device for effecting the adjustment of the linkconnection and controlled by the opposing pressure of fluid in thecompressor-cylinder and in the outlet passage or reservoir of thecompressor, substantially as set forth.

I. In an elastic Huid-compressor, the combination, substantially as setforth, of a compressing-cylinder, positivelyoperated valve mechanismcontrolling the outlet-valves of said cylinder, a pressure-actuatedgoverning device connected to and acting to vary the period of operationof said valve mechanism, valve mechanism controlling the admission ofpressure from the compressing-cylinder to said pressure-actuatedgoverning device, and connections for actuating' said controlling valvemechanism by the actuating mechanism of the outlet-valves.

5. In an elastic Huid-compressor, the com bination, substantially as setforth, of a compressing-cylinder, a motor effecting the funetion offluid compression in said cylinder, valve mechanism controlling theoutlet valves of the co1npressing-cylinder and operated positively bythe motor, a pressureactuated governing device connected to andV adaptedto vary the position of the member through which the met-o1.' operatessaid valve mechanism, valve mechanism controlling the admission ofpressure from the conflpressingcylinder to said prcssure-actlnttedgoverning device, and connections for actuating said controlling-valvemechanism by the actuating mechanism of the outlet-viltlves.

(i. In an elastic {luid-compressor, the combination, substantially asset forth, of a compressing-cylinder, a motor effecting the function ofcompression in said cylinder, valve mechanism controllii'ig theoutlet-valves of the compressing-cylinder, a valve-actuating memberoperated positively by the motorshaft and connected with said valvemeehanism, a pressrue-actuated governing device connected to said valvemechanism and adapted te vary the period of operation imparted to it bythe actuating member, valve mechanism controlling the admission ofpressure from the compressing-cylinder to the pressure-actuatedgoverning device, and conneetions for actuating said controlling-valvemechanism by the actuating mechanism of the outlet-valves- In testimonywhereof I have hereunto set my hand.

FRANCIS l'iI. BITES. l.Vitnessesz T. J'. HOGAN, F. GArrHER.

